Until now, it has been possible to send emergency call messages only from radio cells in which connection-oriented services are available. A document (Tdoc SMG2 EDGE 298/99) which was submitted at the ETSI SMG2 EDGE Workshop from Aug. 24 to 27, 1999 in Paris relates to the sending of emergency call messages from areas of a radio communications system in which only packet-oriented services or only connection-oriented services are available in some radio cells while, in contrast, packet-oriented and connection-oriented services are available in other radio cells. This document proposes that, when an emergency call message is to be sent from a subscriber station in a radio cell with exclusively packet-oriented services, a handover process be initiated for this subscriber station, with the aim of associating the relevant subscriber station with a radio cell with connection-oriented services.
In order to speed up the handover process, Section 11.2.19, page 160 requires that the subscriber station be informed via a signaling channel that connection-oriented services are not available in the originally selected radio cell. A message such as this is advantageous whenever, for example, connection-oriented services are available in one of the adjacent radio cells and this radio cell is selected by the handover process. However, if connection-oriented services are not available in any of the feasible radio cells, a procedure such as this runs into considerable problems.